Method for heat-treating substances packed in sealed receptacles



Aug. 17,1926. 1,596,606

. N. H. FOOKS METHOD FOR HEAT TREATING SUBSTANCES PACKED'INSEALED RECEPTACLES Filed Dec. 5, 1924 lvweu'coz zVeld'on/ fi 1'00706' Patented Au 17,1926.

UNITED STATES PATENT OFFICE.

msorr a. rooxs, or rmaa'rou," MARYLAND.

Application fled December 5, 1924. Serial Io. 754,188.

This invention has for its object to provide an improved method of heat-treating foods in sealed receptacles, such as tin cans, whereby the cooking period may be easily a controlled and the receptacles cooled to reduce the internal pressure therein before being discharged into the atmosphere.

In methods where the receptacles are progressed through a retort along a definite path it has been proposed to control the cooking period by ejecting the receptacles from the retort at a selected point or points in their path of travel. This manner of control not onlyinvolves the employment of more or less complicated and consequently expensive machinery, but also necessitates the discharge of the receptacles into the atmosphere direct- 1y from the heating medium with consequent danger of springing of the seams of the cans and resultant lossof. the product, particularly where the high cooking temperatures are employed.

According to my invention, the sealed receptacles are progressed along a path of definite length within the retort irrespective of the cooking period and are cooled before di'scharge from the same. The retort is filled with superposed fluids maintained at difi'erent temperatures, the cans being passed from one fluid to the other in their course of travel through the retort. To control the cooking period it is merely necessary to raise the level of the fluid of lower temperature. Inasmuch as the cans are progressed through the retort at a definite rate of movement, it follows that they will remain in the fluid of higher temperature a greater or lesser time depending on the depth of the hotter fluid, which depth is controlled by the level of the cooler fluid. The fluid of lower temperature is preferably water and obviously constitutes the cooling medium; the fluid of higher temperature is preferably a gaseous medium, such as steam but may be a heated fixed gas, such as air, or a mixture of steam and .air. The apparatus for carrying out my improved process is extremely simple necessitatin outside of the can-carrying mechanism, re

atively simple means for maintaining the heating and cooling fluids at proper levels I and temperatures.

In the accompanying drawing, Fig. 1 is a part sectional and part diagrammatic elevation of a cooker and cooler in conjunction with which my improved process may .be practiced.

Fig. 2 is a bottom plan view of one group of pipes through which the heating medium is entered into the apparatus shown in Fig. 1.

Inthe drawing Fig. 1 indicates generally a retort or tank provided with a gauge glass tube for indicating the level of the liquid in the retort; 3 a water supply pipe; 4 a pipe or conduit for supplying heating medium to the retort, said pipe having valved 05 lateral extensions 5 each in connection with a group of horizontally disposed pipes generally indicated at 6 and perforated on their bottoms. In filling and maintaining the retort or tank with the heating medium, the latter will be admitted through that group or bank of pipes 6 which is closest to the level of the liquid maintained in the tank, thereby obviating any dead or cold space above the cooling liquid.

The desired level of the cooling liquid is maintained by providing a series of steam traps, generally indicated at 7 at different levels, the traps permitting the cooling 1iq uid to flow out therethrough but not steam, as will be readily understood, the waste pipe ,in connection with said traps being indicated at 8, each trap having a controlling valve 9 exterior thereof to permit the liquid level to be raised to the next higher trap, as will be readily understood. i

The retort or tank is provided with any suitable form of can-conveying means which will permit the cans to be moved at a uniform rate from one level to another in the tank through the heating and cooling'me diums. For simplicity of showing no spe; cific can-moving'means is shown but onlyithe path which the cans will follow in their progress through the tank, such path being indicated at 10 by a line'of cans. When the gaseous medium is maintained under pressure greater than atmospheric pressure the cans may be entered into the retort or tank through a rotary valve 11, and be discharged therefrom by a similar valve 12. However, when the process is practiced without maintaining the gaseous heating medium under pressure, any suitable means for feeding the cans to and receiving them from the endless conveyor may be employed. In the present showing of cooker and cooler the cans after passing through the cooling liquid at the bottom of the tank are shown as passing upwardl through a well 13 formed by a partition 14 and thence outwardly through the discharge valve 12.

It will now be appreciated that in its broadest aspect my invention contemplates the cooking and cooling of substances within sealed receptacles by passing the receptacles through superposed fluids while maintaining the fluids at dilferent temperatures; that when steam is used as the heatingmedium the temperature of the same may be raised by maintaining the steam under pressure greater than atmospheric; that the method of controlling the cooking period is not dependent on maintaining apressure greater than atmospheric pressure within the tank; and that the invention is just as applicable to a so-called open air cooker and cooler as to a pressure cooker and cooler. When the cooling medium is water and the heating medium is a gaseous substance the receptacles will, of course, be progressed through the tank from the top to the bottom thereof inasmuch as the heating medlum will then overlie the water. It may, however, be found desirable to utilize the water as the heating medium and to maintain a suitable cooling medium thereabove for cooling the cans, in which event the cans would obviously be passed from a lower level to a higher level, namely: through the cooking water at the lower level and the cooling medium thereabove. It is also possible to use non-miscible liquids, one of which will serve as the heating medlum and the other the cooling medium.

The desired temperature of the cooling water is kept up by supplying the cooling water through the pipe 3 and the heating medium is maintained by supplylng the same through the conduit 4, as will be readily understood. The gauge glass tube atfords a ready means for determming the level of the liquid within the tank.

The appended claims are intended to define what I consider to be the various novel features of the invention.

I claim:

1. The process of cooking and cooling substances in sealed receptacles, which consists of introducing the receptacles into the top of a fluid cooking medium superposed in direct contact with a fluid, cooling medium, and passing said receptacles in a downward course through said mediums, whereby the contents of the receptacles will be completely cooked during said downward passage through the cooking medium.

2. The process of cooking substances in sealed receptacles which consists of introducing the receptacles into the top of a fluid cooking medium superposed in direct contact with a liquid cooling medium and passing said receptacles in a downward course through said mediums, whereby the contents of the receptacles will be completely cooked during said downward passage through the cooking medium.

3. The process of controlling the cooking and cooling periods of the contents of sealed receptacles while they are being passed continuously through a chamber along a given path from an upper to a lower level therein which consists in keeping the chamber partially filled with acooling medium, maintainmg a heating medium over the body of the cooling medium, and raising or lowering' the level of the cooling medium to decrease or increase, respectively, the yolume of the heating medium, whereby the receptacles remain in the heating medium for a shorter or lesser period of time before entering the cooling medium.

4. The process of controlling the cooking and cooling periods of substances, within sealed receptacles which consists in passing the receptacles in a definite circuitous path through a retort while maintaining therein a gaseous cooking medium above a liquid cooling medium constantly maintained at a cooling temperature, and controlling the cooking period by varying the level of the cooling liquid in the retort.

5. The process of controlling the cooking and cooling periods of substances within sealed receptacles which consists in passing the receptacles in a circuitous path through a heated chamber while maintaining therein a liquid cooling medium and controlling the cooling and cooking periods by varying the level of the cooling liquid in the chamoer.

6. The process of controlling the cooking period of the contents of sealed receptacles which consists in partially filling a retort with -a cooling liquid and maintaining said liquid at a cooling temperature;maintaining 1-1 gaseous heating medium above the cooling medium, passing the receptacles through the heating medium and into the cooling liquid, and raising or lowering the level of the cooling liquid to decrease or increase, respectively, the cooking period of the contents of the receptacles.

7. The process of controlling the cooking period'of substances within sealed receptacles which are being moved at a uniform rate along a definite path from an upper to a lower level in a chamber, which consists in maintaining within the chamber a cooling medium consisting of cool water of less depth than the height of the chamber, maintaining under pressure a body of gaseous heating medium over the body of water,

and controlling the cooking period of the receptacles by varying the level of the water, the path of the receptacles being 1 through the heating and cooling mediums. In testimony whereof I affix my signature.

NELSON H. FOOKS. 

